Peak TV is pushing networks to go big and bold (and often expensive), resulting in a flowering of top-notch sci-fi/supernatural series from 'Westworld' to 'Black Mirror.'

Very quietly over the last few years, an interesting trend has emerged in television: sci-fi and paranormal-themed series have become more prevalent and many of them have spiked, qualitatively, especially in the last year and a half.

While science fiction as a genre has proven irresistible to content creators across the globe because it has a die-hard audience that will sample almost anything, a bigger driving force is that, done well, franchises can sprout amid the critical acclaim, and global hits can emerge from a hungry international audience.

(For the sake of not having to constantly make amendments to the descriptor, let's just use "sci-fi" as a catch-all phrase for true hard-core space series, fantasy, time-travel, altered history and paranormal series — which will save a lot of time. Let's also not reminisce about say, The X-Files, Battlestar Galactica, Lost, Sense8, Continuum, Torchwood, Falling Skies, Orphan Black or any other pet favorites of yore, which are no longer in production, and we might have to disagree about including some of the lighter Marvel and DC fare that is in production and just get on with it.)

If you start with HBO's Game of Thrones as the ur-series that, ever since its debut in 2011, every other channel has been trying to duplicate (both in terms of ambitious world-building and global audience), then the best representations of the genre arguably lead through Netflix's Black Mirror (2011), The CW's The 100 (2014), Starz's Outlander (2014), AMC's Humans (2015), Netflix's Jessica Jones (2015), Amazon's The Man in the High Castle (2015), Syfy's The Expanse and The Magicians (2015), Netflix's Stranger Things, Luke Cage and Travelers (2016), HBO's Westworld (2016), USA's Colony (2016), FX's Legion (2017), CBS All Access' Star Trek: Discovery (2017), Starz's Counterpart (2018), Amazon's Philip K. Dick's Electric Dreams (2018) and, most recently, Netflix's Altered Carbon (2018), which was released on Feb. 2.

Even with plenty of decent sci-fi series left off — and your personal mileage varying on this group — it's an impressive collection of series, with most getting better as they age.

The biggest swings in the early going were Outlander and The Man in the High Castle, as each project was seen as a franchise piece; Starz is no doubt happy with Outlander, but Amazon would probably admit in the dark that it had higher hopes for High Castle finding some Game of Thrones-like success (and Jeff Bezos has since explicitly mandated that the streamer find its own equivalent). For Netflix, Stranger Things came out of nowhere, and the two best series in its high-profile Marvel deal, Jessica Jones and Luke Cage, were critically acclaimed and helped offset weaker counterparts. Westworld then became the blockbuster HBO needed as a replacement for the outgoing Thrones, while Legion (Marvel's best TV series) helped FX expand into a genre it needed to diversify its bench, and CBS built a strong case for its All Access streaming service by taking a beloved franchise in Star Trek and making it relevant as it achieved critical acclaim.

Again, all of this was achieved in the here and now, via a genre that continues to appeal to larger audiences, especially as it grows qualitatively. And don't lose sight of the fact that Syfy, which dedicated sci-fi fans had ridiculed for veeing off-course, strengthened its brand by getting its focus back on creative pursuits like The Expanse and The Magicians (with rabid fans also singing the praises of Killjoys, Wynonna Earp, 12 Monkeys and Ghost Wars). Unlike its competitors, Syfy has to build an entire slate of shows in the genre but has managed, and with a budget far smaller than premium cable and streaming players, to land at least two shows in the discussion about high-end sci-fi franchise building.

It's convenient to say that sci-fi offers escapism for viewers in times of chaos and upheaval, which is also true, but given the timeline here, most of these shows are pre-Trump. A more likely reason for this explosion of amazing offerings is that standing out in the Peak TV clutter demands that platforms with deep pockets spare no expense to put something creatively ambitious and cinematic on the small screen.

But all the series on this list have their own kind of conceptual brilliance and strong execution, no matter the cost. Humans and Colony and The Expanse took time-worn ideas and were able to breathe fresh ideas into them without breaking the bank. Legion was both a visual marvel and a way for FX, known for its grittiness and smarts, to break into sci-fi — and its success validates letting smart creators like Noah Hawley, previously known for the Fargo television franchise, to branch out and play in the sci-fi space.

It's a smart risk for both sides, really. Because a writer like Hawley unleashed on what is essentially a rote superhero framework produced a marvelous piece of television. And if concepts in the sci-fi space click with viewers or create a lot of critical buzz, odds are they will be successful in the international market because they translate across borders better than complicated emotional dramas like, say, Mad Men or The Leftovers (sci-fi series also repeat better and are more likely to be binge-watched).

Even with that knowledge, it's still a little surprising to see how strongly 2018 has started with Counterpart and Altered Carbon (and, with any luck, Philip K. Dick's Electric Dreams can be an anthology series that proves there's room in the market beyond the standard-bearer, Black Mirror). With more new series coming and fresh seasons from most of these listed here just on the horizon, the creative rejuvenation of a genre shows no signs of abating.

A version of this story first appeared in the Feb. 14 issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.